Patent GB-554603-A (GB)
Title: Improvements in or relating to step-by-step mechanisms
IPC: F16H31/00
Filed: 1941-12-08
Abstract: 554,603. Selective signalling. RUBERY OWEN MESSIER, Ltd., and ARNOT, A. Dec. 8, 1941, No. 15808. [Class 40 (i)] [Also in Group XXIV] To prevent overdriving the rotatable driven member has a series of teeth separated by spaces and the reciprocating driving member comprises a pawl or pallet so mounted that it enters substantially radially into the spaces, thus sliding over the teeth but has a component of lateral movement which imparts the driving effort. Receiving arrangements.-The driven member, Fig. 1, consists of a disc 11 with axially projecting pins 13 adapted to be engaged by a pawl 14 sliding in a fixed guide 15 and pivoted at 18 to the core 16 of a solenoid 17. The pawl is notched at 19 and is held down on the guide by a spring 23. The end of the pawl within the circle of teeth is curved to form a pallet 20 which when the pawl is drawn outwards, engages the tooth or pin above it and moves it upwardly. A spring detent 21, 22 holds the disc after each movement. When the pawl has been drawn out fully the pallet 20 still remains between the teeth and prevents overshooting. In Fig. 2 the pawl 34 is pivoted at 38 to a pivoted armature 32 actuated by the core 31 of an electromagnet 30, the pawl riding over a fixed pin 35 being held to this pin by a spring 36 attached to the free end of the pawl which is bent to form an inclined pallet 37. In a modification, the pins extend radially from the disc. In Fig. 3 the magnets and pawls are duplicated to drive the shaft 40 in opposite directions. The pins 13 extend between the disc 11 and a notched disc 41 adapted to be engaged by a detent 43. The magnets are shown at'45, 55 the cores at 46, 56, the armature at 48, 58, the pawls 49, 59 riding over fixed pins 50, 60 to which they are held by springs 51, 61. The shaft 40 is therefore moved step-by-step in either direction according as the magnet 45 or 55 is energized. Transmitter for remote control mechanism as described in Specification 553,789, Fig. 5.-A housing 75 encloses magnets 45, 55 with armatures 48, 58 and pawls 49, 59 which act upon pins 13 between discs 11, 41 as described above. Shaft 40 carries a worm 76 meshing with a worm wheel 77 on a shaft 78 a bevel pinion 79 on which gears with a wheel 80 on a camshaft 81 carrying a contact-operating cam 82. Coaxial with shaft 81 is the hub 83 of a hand lever 84 adapted to be rocked in a slot 85 covered by a plate 86 which can be held against the housing by a nut 87. At the back of the hub 83 is a flange 90 an insulating block on which carries contacts 92, 93 connected by flexible strips 94 to terminals 95. Between the contacts is a spring contact arm 96 secured at 97 to the side of the hub. A cam follower in the form of a sliding pin 98 lies between the cam and the spring. Movement of the lever 84 in one or other direction will cause the spring arm 96 to contact with 92 or 93. The circuit is so arranged that if contact 93 is engaged, the magnet 55 is energized and the pin wheel 11 is rotated clockwise and through the shaft 78 and gearing 79, 80, the cam is rotated anticlockwise to push out the follower and break the contact. If the arm 84'is moved in the opposite direction, contact 92 is engaged the magnet 45 is energized and the cam rotated to again break the circuit. The electrical connections are described with reference to Fig. 6 (not shown).